Event Based XML Parsing SAX - Count Number of Elements

// Event Based XML Parsing – SAX

import javax.xml.parsers.*;

import org.xml.sax.*;

import org.xml.sax.helpers.DefaultHandler;

 

/** Helper class containing SAX event handler methods */

class CountElements extends DefaultHandler

{

     /** Number of 'p' elements seen so far */

     int numElements;

    

     /** Constructor (allows for superclass initialization) */

     CountElements()

     {

          super();

     }

    

     /** Perform initialization for this instance */

     public void startDocument() throws SAXException

     {

          numElements = 0;

          return;

     }

 

     /** Process the start of an element */

     public void startElement(String namespaceURI, String localName,        String qName, Attributes attr) throws SAXException

     {

          if (qName.equals("rss"))

          {

              numElements++;

          }

          return;

     }

 

     /** Done with document; output final count */

     public void endDocument() throws SAXException

     {

          System.out.println("Input document has " + numElements + " 'rss' elements.");

          return;

     }

}

 

 

/** Count the number of link elements in an XML document */

class SAXCountLinks

{

     /** Source document */

     static String FEED_URL = "rss.xml";

 

     static public void main(String args[])

     {

          try

          {            

              SAXParserFactory saxFactory = SAXParserFactory.newInstance();

              XMLReader parser = saxFactory.newSAXParser().getXMLReader();

 

              parser.setContentHandler(new CountElements());

              parser.parse(FEED_URL);

          }

          catch (SAXParseException spe)

          {

              System.err.println("Parse error at line " + spe.getLineNumber() + ", character " + spe.getColumnNumber());

              if (spe.getException() != null)

              {

                   spe.getException().printStackTrace();

              }

              else

              {

                   spe.printStackTrace();

              }

          }

          catch (SAXException se)

          {

              if (se.getException() != null)

              {

                   se.getException().printStackTrace();

              }

              else

              {

                   se.printStackTrace();

              }

          }

          catch (Exception e)

          {

              e.printStackTrace();

          }

          return;

     }

}